One Minute Mac Tip: Open multiple Tor circuits in the new TorBrowserBundle 3.5 for Mac OS X

Earlier this month, the Tor Project released a new version of the Tor Browser Bundle, an easy-to-use anonymity-enhancing Web browser. In a previous post, I discussed how to use the Tor Browser Bundle (TBB) for other applications on your computer, such as Safari and even Mail.app. This post has updated instructions for doing some of the “fancy” things that the new TBB no longer provides a graphical user interface to do.

As of version 3.5, the Tor Browser Bundle on Mac OS X no longer ships with Vidalia, the GUI that lets you configure your connection to the Tor network. Instead, this is packaged as a Firefox add-on called TorLauncher. This add-on doesn’t have any GUI yet, but since it’s still a full-fledged Tor, you can access its advanced features using Tor’s configuration file.

From the Finder, right-click (or control-click) on the TorBrowserBundle application and select “Show Package Contents.” A window will open showing the folders and files that make up the application bundle. The file we’re looking for is called torrc-defaults, which the TorLauncher uses to configure the Tor (essentially the equivalent of Vidalia’s old “Settings” screen). That file is located in Data/Tor/torrc-defaults, as shown below:

Open the torrc-defaults file with any text editor (such as TextEdit). Its contents are a tor configuration file, and they’re pretty simple:

Using configuration directives in this file, you can tell Tor to, for example, use a specific country as an exit node so that you appear to always be accessing websites from the country you specify (useful for avoiding country restrictions on video content). You can also use it to open multiple Tor circuits for privacy reasons, as discussed in my previous post. That’s what we’re going to do.

To set up multiple circuits, simply delete the line that starts with SocksListenAddress and replace it with a line that reads like SocksPort 9050 (where 9050 is whatever port you want to use as your additional circuit). Here’s what my torrc-defaults looks like: